1. Field of the Invention
This invention relates generally to vehicle-mounted utility carriers and more particularly to vehicle-mounted utility carriers mountable to ball-type trailer hitches.
2. Description of the Prior Art
A utility carrier mounted to the rear of a vehicle can be very useful for transporting vehicle accessories such as a ski rack, utility box, bicycle rack or the like, particularly if the carrier (1) is adapted to be mounted to a ball-type trailer hitch capable of other uses as well and (2) can be mounted and detached quickly and easily without the use of tools.
Many prior utility carriers, such as those shown in Prue U.S. Pat. No. 4,138,152; Spencer U.S. Pat. No. 3,853,255 and Johannes U.S. Pat. No. 3,606,385, are not adapted to be mounted to ball-type trailer hitches and thus require the use of specialized hitches to which the carrier is attached. Such carriers also require the use of tools to mount and detach the carrier. Consequently, the carriers either must be mounted semi-permanently to the vehicle or periodically mounted to and detached from the vehicle with great effort.
Other prior utility carriers, such as those shown in Haas U.S. Pat. No. 3,858,775 and Haskett, et al. U.S. Pat. No. 3,650,443, are adapted to be mounted to ball-type trailer hitches, but such carriers still require the use of tools for complete mounting and detaching of the carrier. Consequently, such carriers cannot be mounted to and detached from the vehicle quickly and easily, an important feature if the trailer hitch or rear end of the vehicle is to be used for other purposes.
A few prior utility carrier constructions, such as those shown in Schwartz, et al. U.S. Pat. No. 3,805,984; Goldstein U.S. Pat. No. 3,796,333 and Wilson U.S. Pat. No. 3,724,694, are adapted to be mounted to ball-type trailer hitches without the use of tools. However, such carriers tend to be of a rather complex construction and still cannot be mounted to and detached from the vehicle quickly and easily. For example, the carrier shown in Wilson has two support arms which are secured to the underframe of the vehicle. One must crawl under the vehicle to tighten or loosen the thumbscrews securing the arms to the underframe, depending upon whether the carrier is being mounted to or detached from the vehicle. The carrier shown in Goldstein is designed so that a tongue of the trailer hitch must be precisely aligned with a pair of complementary-shaped opposing channels within which the tongue is slidably received, a difficult task for a single person if the carrier is of a heavy, sturdy metal construction. As for the carrier shown in Schwartz, et al., it has several parts which must be assembled before the carrier is mounted to the trailer hitch.
The above "ball" hitch-mounted carriers have an additional disadvantage. They do not make adequate use of the main component of the trailer hitch--the hitch ball. They use the hitch ball only as a support to carry all or a portion of the weight of the carrier and as part of a locking mechanism to prevent complete disengagement of the carrier from the hitch, but not in a manner which eliminates all pivoting and sliding movement of the carrier relative to the hitch. Consequently, the load which the carrier is able to support is inherently limited and the amount of wear to which many parts of the carrier are subject as a result of the movement is substantial.
Of general interest is the boat loader shown in Ball U.S. Pat. No. 3,976,213.
Accordingly, there is a need for a utility carrier of simplified construction which is adapted to be mounted to a ball-type trailer hitch without the use of tools and which is mountable to the hitch in a manner such that all movement of the carrier relative to the hitch is positively prevented.